Problem: What's the first wrong statement in the proof below that $ \triangle BCE \cong \triangle BDE$ $ \; ?$ $ \overline{BC} $ is parallel to $ \overline{DF} $. This diagram is not drawn to scale. $A$ $B$ $C$ $D$ $E$ $F$ Givens $ \angle ACB \cong \angle BDE$ $, \ $ $ \overline{AC} \cong \overline{DE}$ $, \ $ $ \angle BAC \cong \angle BED$ $, \ $ $ \angle CEF \cong \angle BED$ $, \ $ $ \overline{EF} \cong \overline{BE}$ $, \ $ and $\ $ $ \angle CFE \cong \angle DBE$ Proof $ \triangle BDE \cong \triangle FCE$ because ASA $ \overline{DE} \cong \overline{CE}$ because corresponding parts of congruent triangles are congruent $ \triangle BDE \cong \triangle BCA$ because ASA $ \overline{BD} \cong \overline{BC}$ because corresponding parts of congruent triangles are congruent $ \triangle BDE \cong \triangle BCE$ because SSS
Answer: Try going through the proof yourself: write down the givens, and then see if they justify the next step for the reason given. Then do the same thing for the next step, and the next, until you run into something that you can't justify, or you finish the proof. There is no wrong statement in this proof.